1. Field of the Invention
This invention relates to a sheet (e.g., printing paper sheet) particularly for printing with a high-definition thermal mass transfer printer.
2. Description of the Background Art
Transparent oriented polyester film, oriented white polyester film having an internal inorganic filler, oriented synthetic paper utilizing polypropylene resin with cushioning property (e.g., Yupo, product of Oji-Yuka Synthetic Paper Co., Ltd.), oriented polyolefine film or the like coated with an ink receiving layer have conventionally been used as sheets for printing with thermal mass transfer printers.
The sheet consisting of polyester film coated with an ink receiving layer exhibits high printing density but is expensive and an unpleasant feel.
The sheet consisting of oriented polyolefine film coated with an ink receiving layer exhibits high printing density, has good feel and can be used when high resolution is not required (when the definition is not high).
When the printer resolution is increased for achieving high definition, however, the quality of the printing is poor owing to poor dot registration when several colors are printed one on top of another.
This is thought to be due to stretching (elongation) of the sheet during feed. Specifically, when several colors are printed one on another in high-resolution printing, the sheet is squeezed within the printer for precise positioning of the dots, and this is thought to cause elongation.
Similarly, when oriented polypropylene film is used for printing with a high-definition printer, the printing quality is degraded when several colors are superimposed since the dots do not register well.
Some sheets available for printing with high-definition printers enable high printing density and good dot registration but have poor texture (feel), while others have good feel but poor dot registration. None of the prior art sheets provides both good feel and good printing quality (no dot shift when several colors are superimposed).